The present invention relates to borax neutralized phosphate esters (mono and/or diesters, predominantly monoesters) which, when preferably at least partially neutralized separately, or in situ, are revealed as novel emulsifiers. Formulations are presented also which demonstrate a method for using the disclosed emulsifier to prepare stable emulsions of varying polarity and viscosity for use in a variety of dermatological applications, and/or wherever this type of emulsion may be useful.
From 1982 to 1995 the inventor marketed and sold diethanolamine (DEA) cetyl phosphate under the commercial name Amphisol(trademark), as a technical sales representative for the Givaudan Corp. (Division of Hoffmann-LaRoche). A group of formulations including sunscreens, skin treatment and pigmented lotions, among others were formulated and demonstrated to help sell the Amphisol(trademark) to sunscreen and skin care companies.
In the early 1990""s, in Europe and in the United States in 1999, DEA derivatives became suspect and then undesirable for use because of possible nitrosamine formation and health concerns which emerged from this information.
In or about 1992-93, Amphisol(trademark) K (the potassium salt of cetyl phosphate) was introduced to replace the Amphisol(trademark) and thus eliminate the DEA. Amphisol(trademark) K however, never functioned as well as the original Amphisol(trademark) in certain applications. To this day, there is a desire by all users of Amphisol(trademark) (who favor its inherent properties in making unusually stable oil-in-water emulsions) for a direct replacement which does not incorporate diethanolamine.
As early as 1957 the inventor was aware of the use of a beeswax-borax system to prepare water-in-oil emulsions. Although the system functions reasonably well, problems emerged as beeswax varied from batch to batch and produced quality control problems. In addition, compositions utilizing beeswax often required strenuous mixing or homogenization to facilitate the production of a stable final formulation.
In order to address the shortcomings of beeswax/borax, the present inventor invented emulsions based upon the neutralization product of 12-hydroxystearic acid. These formulations are described in U.S. Pat. No. 5,993,861, issued Nov. 30, 1999.
These diverse teachings and the inventor""s experience after almost 40 years of research, led to the inventor""s attempt to find an adequate replacement for the diethanolamine used in (DEA) cetyl phosphate, inasmuch as the art had failed to find an adequate replacement.
It is an object of the invention to provide phosphate ester surface active agents which function as one or more of emulsifiers, wetters, spreaders, dispersers, detergents, foamers and emollients to provide storage stable emulsions, among other compositions.
It is a further object of the invention to provide phosphate ester emulsifiers which can function as a direct replacement for diethanolamine (DEA) cetyl phosphate (Amphisol(trademark)).
It is an additional object of the invention to provide a method of making emulsions which are easy to formulate and provide for accurate quality control.
It is yet another object of the invention to provide emulsions which can be used to readily manufacture personal care products including cosmetic products such as sunscreens, skin care lotions and creams as well as a myriad of other types of products.
These and/or other objects of the invention may be readily gleaned from the detailed description of the invention which follows.